The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 26, 2001
Filed:
Feb. 18, 2000
Richard J. Gustafson, Columbus, IN (US);
Cummins Engine Company, Inc., Columbus, IN (US);
Abstract
A unit fuel injector adapted to receive fuel from a fuel supply at relatively low pressure and adapted to inject fuel at relatively high pressure into the combustion chamber of an internal combustion engine is provided, comprising an injector body having a first internal bore and an injector orifice and a plunger mounted for reciprocating movement within the first internal bore to define a variable volume fuel pressurization chamber including a cam actuated upper plunger portion and a lower plunger portion mounted in the first internal bore between the variable volume fuel pressurization chamber and the upper plunger portion. While the upper plunger portion is in its retracted position, low pressure fuel from the fuel supply is supplied to the variable volume fuel pressurization chamber. A spring is positioned within the first internal bore to bias the upper and lower plunger portions apart to thereby allow for variation of the volume of fuel which flows into the variable volume fuel pressurization chamber during each cycle of injection operation in dependence on the pressure of the fuel from the fuel supply. A valve assembly including a valve element mounted for reciprocating movement within a second internal bore controls the flow of fuel from the variable volume fuel pressurization chamber to the injector orifice. The valve assembly allows fuel to be discharged through the injector orifice only during the time when the upper plunger portion is in its fully advanced position so that injection pressure is independent of the velocity at which the upper plunger portion moves between its retracted and advanced position.